Various scientific articles and patents are referred to throughout the specification. These publications are incorporated herein by reference to describe the state of the art to which this invention pertains and to provide details on standard methodologies and apparatuses which may be useful in practicing various embodiments of the present invention.
Polyaromatic hydrocarbons (PAHs) are widespread, common pollutants particularly found in association with oil refineries, certain refined petroleum products, petroleum storage locations, and petroleum spill sites. High levels of PAHs are associated with mutagenic and carcinogenic effects in humans and pose a high risk for migration to and pollution of soil and ground water sources. As a result, there has been considerable interest in techniques and processes which will degrade PAHs and related petroleum products to remediate the environment. The uses of biological agents to treat PAHs are well known within the art. U.S. Pat. No. 6,503,746 to Daane describes bacterial strains in the family Bacillaceae which are used in PAH remediation efforts.
U.S. Pat. No. 3,616,204 to Linn discloses inoculating contaminated soil with cultures of microorganisms known to degrade the unwanted contaminants. The procedure described in Linn additionally involves introducing nutritional supplements to increase the soil remediation efficiency.
U.S. Pat. No. 5,100,455 to Pickard discloses using indigenous microflora and fauna in combination with humic substrates to biologically treat soil contaminants including petroleum associated hydrocarbons.
U.S. Pat. No. 4,849,360 to Norris discloses a bioreactor for treating petroleum contaminated soil in which air is forced through the contaminated soil to facilitate the bioremediation. The bioreactor uses indigenous microflora which are supplemented with phosphorus and nitrogen nutrients.
While a variety of PAH-degrading bacteria are known and have been utilized in various applications for remediation, there remains a need for improvement in the art in terms of identifying new and useful species having novel properties which are effective for the rapid degradation of petroleum pollutants.